Fig. 3: K130 is required for SERINC5 localization to the plasma membrane.

A Ser5-GFP and its lysine mutants were expressed in HeLa cells. Cells were stained with DAPI (4′,6-diamidino-2-phenylindole) for the nuclei (blue) and DiIC₁₈(5) for the plasma membranes (far-red) (bottom panel) or only stained with DAPI (top panel). In addition, Ser5-GFP and its K130R or 1-19 K/R mutant were expressed in Jurkat cells, and cells were stained with DAPI. Subcellular localization of these Ser5 proteins was detected by confocal microscopy (scale bar 2 or 5 µm). Experiments were repeated twice, and representative experiments are shown. B Ser5-iFLAG and its lysine mutants were expressed in HEK293T and Jurkat cells. Cells were stained with anti-FLAG and levels of Ser5 on the cell surface were analyzed by flow cytometry. Results are shown as relative values, with the surface expression of WT Ser5 set as 100. Error bars indicate SEMs calculated from three experiments. n = 3; One-way ANOVA Tukey test; ns, not significant; *p < 0.05, **p < 0.01, ***p < 0.001. C Ser5, its lysine mutants, and CD4 were expressed in HEK293T cells. The plasma membranes from these cells were purified and analyzed by WB. Experiments were repeated twice, and similar results were obtained. Source data are provided as a Source Data file.